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Post by Steve P5b on Jun 16, 2015 9:10:27 GMT
Sure Steve, happy to do that for you. Unfortunately I'm currently away for a few days and don't have them to hand. Have you tried the mount in 'extension' by placing load between the 2 halves by using a tyre lever or similar device to see what degree of separation can occur under this type of loading? Yes, an 18 inch tyre lever tilted the top over with no sign of separation at all. That is not what I had expected. Having driven the car with these temporary blocks of wood in place I noted the steering had tight spots, having a look the coupling between the steer box and column is under stress due to the subframe not being in its usual location ( the blocks are 6mm thicker than the mounting) indicating that the mountings weren't too compressed to start with. If you could measure the mounting thickness on your car and a new one on the bench it would be a good indication as to the condition for others also. Many thanks for the offer. Steve
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Post by enigmas on Jun 16, 2015 9:37:18 GMT
Steve that's the sort of thing I was intimating. It's great that the mounts are still so durable even when they apparently appear in poor shape but it's bad engineering practice to have the subframe impose any load on the steering coupling. These loads, up down and sideways are placed on a rigidly mounted steering box with only a rubber and fabric coupling to compensate for misalignment. Imagine the stresses imposed on the steering box (especially on rough roads.) If you disconnect the steering coupling then insert a spacer of the correct thickness between the body and the subframe until the shafts are directly aligned then there will be no initial loads imposed on the steering box. This is how it should have been initially setup.
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Post by Deleted on Jun 16, 2015 10:12:34 GMT
I'm glad my car's in the garage at the moment as I think I'd be afraid to drive it Springs falling away from the body when changing a wheel due to a "design fault" with the contrasonics, single circuit brakes, brittle petrol hoses, dodgy electrics, brake pedal connections failing and now a "design fault" on the sub frame which nobody has noticed for 45 years
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Post by enigmas on Jun 16, 2015 11:23:15 GMT
Do whatever makes you feel comfortable and secure but don't add or modify anything non original after the original build date if that is your defining focus for your car. This may include: radial ply tyres, higher rated electronics including: alternator, head lights, relays , inertia reel seat belts, non asbestos brake linings, or kunifer brake lines and legal, braided flexible brake hoses to improve the safety and efficiency of the single circuit brakes. Any commentary or view point is purely for discussion purposes, not a sermon from the mount. No one is forcing you to read it or react. Perhaps what Steve or I do by being willing to do it (on our cars) may benefit someone else who doesn't want to experiment.
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Post by Deleted on Jun 16, 2015 12:28:07 GMT
In the years since the P5s were designed car design and technology has progressed.There have been many changes in metallurgy and assembly techniques. To use some of this progress to improve the driving experience or performance of these cars,preferably without loosing their character and identity is surely worthwhile. After all Rover continually developed the cars during their production run.
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Post by Phil Nottingham on Jun 16, 2015 17:48:51 GMT
Not at all convinced that the original was a bad design or even that yours were bad enough to do anything about it yet but having got this far why not just try it to see the difference as I basically agree with Enigmas - the P5 body shell as long as is not excessively rust compromised which many are or have been should hardly be affected
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Post by Steve P5b on Jun 16, 2015 20:01:57 GMT
Steve that's the sort of thing I was intimating. It's great that the mounts are still so durable even when they apparently appear in poor shape but it's bad engineering practice to have the subframe impose any load on the steering coupling. These loads, up down and sideways are placed on a rigidly mounted steering box with only a rubber and fabric coupling to compensate for misalignment. Imagine the stresses imposed on the steering box (especially on rough roads.) If you disconnect the steering coupling then insert a spacer of the correct thickness between the body and the subframe until the shafts are directly aligned then there will be no initial loads imposed on the steering box. This is how it should have been initially setup. Talking over this made me realise that if there is movement between the subframe and body it would manifest itself loading the steer box input shaft as the coupling there isn't flexible enough to compensate. So I'm thinking with age and the mountings collapsing the load on the steer box causes premature wear and oil leakage. Just a thought. A nd as Enigmas says Imagine the stresses imposed on the steering box (especially on rough roads.)Read more: roverp5.proboards.com/thread/9050/front-subframe-rubber-mounts-all?page=3#ixzz3dG3PUaFQMaybe a good reason to connect both subframe and body rigidly
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Post by Steve P5b on Jun 16, 2015 20:08:07 GMT
Not at all convinced that the original was a bad design or even that yours were bad enough to do anything about it yet but having got this far why not just try it to see the difference as I basically agree with Enigmas - the P5 body shell as long as is not excessively rust compromised which many are or have been should hardly be affected Not too sure what your suggesting Phil, do you mean go forward with converting the mounts so as they become solid? I do agree that the condition of these mounts is impressive even though there appearance would suggest of poor performance.
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Post by bissmire on Jun 16, 2015 20:18:20 GMT
Thought I'd share my mounts, went for solid to aide handling.
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Post by Steve P5b on Jun 16, 2015 20:23:11 GMT
Thought I'd share my mounts, went for solid to aide handling. Please enlighten us.
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Post by bissmire on Jun 16, 2015 20:38:44 GMT
My suspension front and rear is a heavy modified rose jointed affair, didn't want any potential movement between monocoque and subframe...However small.
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Post by Deleted on Jun 16, 2015 21:32:39 GMT
I'm sure these mounts are more to help slight differences in alignment and to avoid a direct path for the transmission of vibration than to accommodate actual movement.
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Post by enigmas on Jun 17, 2015 4:44:32 GMT
Nice work on the mounts Bissmire...they certainly look professionally done. I'll have to fabricate something like that myself.
I can see know that I'd like to substitute at least 4, directly replacing the front mounts and ensuring that there's no undue load imposed on the steering box coupling.
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Post by Steve P5b on Jun 17, 2015 7:11:53 GMT
Nice work on the mounts Bissmire...they certainly look professionally done. I'll have to fabricate something like that myself. I can see know that I'd like to substitute at least 4, directly replacing the front mounts and ensuring that there's no undue load imposed on the steering box coupling. Yes I agree, and they do look sufficiently strong enough. What with brake pipe movement and steering couplings under stress it would appear there is a lot to be said for solid mountings.
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Post by Deleted on Jun 17, 2015 7:22:28 GMT
Does anyone know how many p5s or p5bs that have suffered from collapsed steering couplings or sheared off brake pipes. Even given the number of cars and the vast numbers of miles driven over fifty plus years of the models history I doubt there are many. The idea of a rubber mounted subframe is hardly unique to the rovers either.
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Post by Deleted on Jun 17, 2015 8:54:06 GMT
Does anyone know how many p5s or p5bs that have suffered from collapsed steering couplings or sheared off brake pipes. Even given the number of cars and the vast numbers of miles driven over fifty plus years of the models history I doubt there are many. The idea of a rubber mounted subframe is hardly unique to the rovers either. I've been a member of the club since the 1980's and on this forum since 2005. I've owned my car since 1980 and I can honestly say this is the first time that these potential problems have been raised (to my knowledge).
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Post by enigmas on Jun 17, 2015 9:40:43 GMT
Resurgam said, "I've been a member of the club since the 1980's and on this forum since 2005. I've owned my car since 1980..."
You've missed the point...again! This is not a contest nor is it prescriptive!
If you're pleased with the performance of your totally original P5B, then that's fantastic for you. Just enjoy it.
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Post by Deleted on Jun 17, 2015 12:53:40 GMT
I'm all for modifying and altering to improve performance or comfort etc. The original design was OK for the time but design has moved on since. One things for certain the car generates lots of loyalty from owners in a way few others do long may it be so.
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Post by Phil Nottingham on Jun 17, 2015 17:54:05 GMT
Too much overthinking IMHO - worry about things that will happen rather than may happen once in a blue moon
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Post by Deleted on Jun 17, 2015 19:47:26 GMT
Resurgam said, "I've been a member of the club since the 1980's and on this forum since 2005. I've owned my car since 1980..." You've missed the point...again! This is not a contest nor is it prescriptive! If you're pleased with the performance of your totally original P5B, then that's fantastic for you. Just enjoy it. I was responding to kev and just pointing out that, to the best of my knowledge, in all the years of ownership etc, these problems have never been mentioned before. I'm not missing any points and certainly not in a contest whatever that means.
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Post by Colin McA on Jun 17, 2015 23:44:11 GMT
The solid mounts look good.
I wonder how they would compare on a car with radial tyres and standard isolators on crossplies, i would think it would be similar if not better on solids.
The late mini i had there was an option for solid mounts. They were an alloy but I couldnt tell the difference other than they wouldnt fall apart and move.
Colin
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Post by Roy of the Rovers on Jun 18, 2015 10:17:47 GMT
I've been reading this with interest but don't have any useful input other than a question.
Im reading there seems to be concern that original mounts do their job but perhaps don't give the 'feel' of a solidly mounted subframe. The solid mounts could cause stress to the P5 body. And also could modern rubber last? Its often said it doesn't contain the 'good stuff' that the originals were made with.
As a compromise would a 'soft' compound of polybush material be suitable? Giving more support and feel than the original rubber one, but still with a little 'give' that the solid mounts can't provide. Should be easy to make and isn't it supposed to last longer too?
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Post by enigmas on Jun 18, 2015 14:38:43 GMT
With growing trepidation, I'll provide a response Roy. Given the car's original design brief the original subframe mounts are satisfactory. If the dynamics of handling, braking, steering and suspension control is to be improved, the total chassis needs to be made a more stable, singular platform. A mount made totally from a synthetic product may provide another solution for those interested in pursuing it, but who would invest the time on the R & D.
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Post by Phil Nottingham on Jun 18, 2015 18:05:35 GMT
Will it be a P5B then ?- safety and mandatory current legislation mods are one thing but where does it stop this will turn the car into a replica or retro vehicle - almost like the BMW Mini If new parts or good secondhand ones for limited use classics are NLA then there is no choice - surely the somewhat slack road-holding which was good for the time and price is part of the attraction of classics of any make and as far as modern cars are concerned they can keep their so called improvements as far as I am concerned Much more on this topic I may moderate it to "Modified!
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Post by enigmas on Jun 18, 2015 22:23:35 GMT
Phil there are NOS and repro mounts still available for those who want to maintain the original classic experience of the Rover P5/B whether sedan or coupe. There are also a few individuals who want something else or more from their cars and modify them to varying degrees to enhance their experience of their car. This is the nature of a free society, to pursue an interest or focus without censure as long as it doesn't impact negatively upon other individuals. The only contentious issue that has arisen by virtue of a technical discussion here is the questioning of individual/personal viewpoints about how things should be done or be allowed to be done. This limits technical discussion and forum participation. How many individuals sit back and don't post their views due to this?
You have a point though, perhaps there should be 2 separate topics with regard to maintenance and replacement of components. One could be: How I maintained my factory original P5/B by sourcing NOS components into the 21st century.
And the other...
How I maintained my Rover P5/B into the 21st century by using a mix of original/repro/and custom fabricated parts/components to suit my individual focus for the car.
I think it would allow for a more seamless technical discussion with less aggravation for both viewpoints.
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